CIE 220 PDF

CIE 220 –

Technical Report, developed by TC 1-90, is a research report describing a general colourfidelity index, Rf, as a scientifically accurate measure of colour fidelity with respect to areference illuminant. The important improvements of this measure, relative to the currentcolour rendering index, are the update of the colour difference calculation, in particular theobject colour space, and the incorporation of 99 test-colour samples which provide a moreuniform distribution of slope and curvature values as a function of wavelength and which havecolour appearance values that are more widely and uniformly distributed in the threedimensions of a uniform colour space. However, Rf is not a replacement of the general colourrendering index, Ra, neither for the purpose of rating and specification of products nor forregulatory or other minimum performance requirements. Finally, relations of Rf to Ra and toluminous efficiency are discussed.